全RE?

在DEV上编译测试通过，为什么这里不行QAQ

#include<iostream>
#include<cstring>
#include<cmath>
using namespace std;
bool array[10000001];

int esp(int b) {
    memset(array,true,sizeof(array));
    array[1] =array[0] = false;
    int n = sqrt(b);
    for(int step = 0; step <= n; step++) {
        if(array[step]) {
            for(int j = 2; j <= b/step; j++)
                array[step * j] = false;
        }
    }
}

bool hw(int b) {
    int temp = b,ans = 0;
    while(temp != 0) {
        ans=ans*10+temp%10;
        temp /= 10;
    }
    if(ans == b)return true;
    return false;
}

int main() {
    int a,b;
    cin>>a>>b;
    esp(b);
    if (a%2==0) a++;
    for (int i=a; i<=b; i+=2) {
        if (array[i] && hw(i))
            cout<<i<<endl;
    }
    return 0;
}